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IVES 9 IVES Conference Series 9 THE ODORIFEROUS VOLATILE CHEMICALS BEHIND THE OXIDATIVE AROMA DEGRADATION OF SPANISH RED WINES

THE ODORIFEROUS VOLATILE CHEMICALS BEHIND THE OXIDATIVE AROMA DEGRADATION OF SPANISH RED WINES

Abstract

It is a well-established fact that premature oxidation is noxious for wine aromatic quality and longevity. Although some oxidation-related aroma molecules have been previously identified, there are not works carrying out systematic research about the changes in the profiles of odour-active volatiles during wine oxidation.

Different types of wines in terms of region, grape variety, oak aging and price were subjected to an oxidative aging procedure, sensory analysis, gas-chromatography olfactometry (GC-O) and quantitative analysis. Sensory notes such as dried fruit, cooked vegetables or liquorice-alcohol were oxidation-related. The GCO analysis of the samples with highest oxidation notes, revealed highest levels of four odour zones, which were identified in a dual system GC-O/FID-GC-O/MS as 1,1-diethoxyethane (liquor, strawberry, sweet), 2,4,5-trimethyl-1,3-dioxolane (fruity, solvent), 3-methylbutanal (solvent, yeasty) and methional (boiled potato, cooked vegetables).

The two aldehydes were quantified by gas chromatography-mass spectrometry (GC-MS). together with isobutanal, 2-methylbutanal and phenylacetaldehyde. All them were already present in significant amounts before oxidation. However, as they were forming odourless reversible adducts with SO₂ (α-hydroxyalkylsulphonates)1 they were initially non-odour active. However, as free SO₂ disappeared during oxidation² they become odour-active in oxidized samples. Additional quantities were formed during oxidation, most likely by the reaction of wine dicarbonyls with the amino acid precursors. This additional formation was particularly relevant for 2-methylbutanal, followed by methional and isobutanal, while for phenylacetaldehyde and 3-methylbutanal, quantities formed were smaller than those originally present. These results confirm that both, pre-existent levels of Strecker aldehydes and the ability to form them during oxidation, are relevant in wine stability.

Acetals were determined by L-L microextraction followed by GC-MS. Results revealed that during oxidation there is a clear increment on the levels of acetals formed from the condensation of acetaldehyde with ethanol, 2,3-butanediol and glycerol; leading to 1,1-diethoxyethane, 2,4,5-trimethyl-1,3-dioxolane and several heterocyclic acetals, respectively. Levels formed were high enough to be odour-active. This suggests that the formation of acetals is an essential part of the sensory changes noted during wine oxidation.

 

1. L.C. de Azevedo et al., Journal of Agricultural and Food Chemistry 2007, 55 (21)
2. M. Bueno, V. Carrascón & V.Ferreira. Journal of Agricultural and Food Chemistry 2016, 64 (3)

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

A. M. Aragón-Capone¹, A. de-la-Fuente-Blanco¹, M.P. Saenz-Navajas², V.Ferreira¹, M.Bueno¹
1. Laboratorio de Análisis del Aroma y Enología (LAAE), Departamento de Química Analítica, Universidad de Zaragoza, Institu-to Agroalimentario de Aragón (IA2) (UNIZAR-CITA).Associated to Instituto de Ciencias de la Vid y del Vino (ICVV)(UR-CSIC-GR), c/Pedro Cerbuna 12, 50009 Zaragoza, Spain.
2. Instituto de Ciencias de la Vid y el Vino (ICVV) (UR-CSIC-GR), Departamento de Enología, Logroño, La Rioja, Spain.

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Keywords

Chemosensory analysis, Gas chromatography-olfactometry (GC-O), Oxidative aging, Wine’s longevity

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

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